1. Field of the Invention
The present invention relates to an electronic component mounting apparatus for mounting electronic components on a substrate, and to an electronic component mounting method.
2. Description of the Related Art
When in use, an electronic component mounting apparatus repetitively performs a mounting operation, wherefor a mounting head is employed, to securely mount on a substrate electronic components supplied by an electronic component feeding unit. Of the electronic components thus supplied, an electronic component such as a flip chip, on the surface of which are formed bumps, projecting electrodes used for connections, is generally fed with the bump formation surface facing upward.
Such an electronic component is extracted from the electronic component feeding unit by a special pickup device, for which an inversion mechanism is provided, and is inverted and is held with the bumps directed downwards. The mounting head, for mounting the electronic component on the substrate, receives the electronic component in the inverted state, and at a flux transfer stage performs an operation whereby a flux is transferred and applied to the bumps. Then, the mounting head is moved to the substrate, whereon the electronic component is thereafter mounted.
A conventional electronic component mounting apparatus is so designed that a mounting head for mounting an electronic component on a substrate also serves as a work head for performing a flux transfer operation. And since during a flux transfer operation a flattening operation is also frequently performed to shape the bumps on an electronic component, by pressing the lower ends of the bumps against a flat face, the mounting head also requires a mechanism for performing the flattening process. Therefore, since the strength of the mounting head must be increased to withstand the strain imposed by the application of pressure, the degree to which the structure of the mounting head can be simplified, and its weight reduced, is limited, and an increase in the speed of the mounting operation is precluded.
Further, even for a case wherein the flattening process is not required, the flux transfer operation and the mounting operation are supposed to be sequentially preformed by the same mounting head. Therefore, the tact time from when the electronic component is extracted until it is mounted on the substrate is delayed, and improving the overall working efficiency is difficult.